@inproceedings{oai:jaxa.repo.nii.ac.jp:00005627, author = {Yang, Choongmo and 青山, 剛史 and 石井, 寛一 and 奥野, 善則 and Yang, Choongmo and Aoyama, Takashi and Ishii, Hirokazu and Okuno, Yoshinori}, book = {宇宙航空研究開発機構特別資料: 第39回流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム2007論文集, JAXA Special Publication: Proceedings of 39th Fluid Dynamics Conference/Aerospace Numerical Simulation Symposium 2007}, month = {Feb}, note = {Blade-Vortex Interaction (BVI) is known to be one of the most annoying sources of helicopter noise. In order to obtain acoustic waveforms of BVI noise, a series of flight tests was conducted by JAXA's MuPAL-epsilon (Multi-Purpose Aviation Laboratory-epsilon) research helicopter using a microphone mounted on its nose boom. The measured acoustic data of the flight tests shows apparently stronger BVI noise in turning flight than in straight flight at the same airspeed and vertical speed. From the flight conditions, two cases, a straight descent and a descending turn, are chosen to compare the noise pattern with CFD (Computational Fluid Dynamics) computation and to understand the BVI noise characteristics during coordinate turns. Trim data obtained through a flight simulation code are given to CFD computation for two cases. CFD simulation successfully reproduces the tendency of increasing BVI noise due to the turning maneuver at least for the present flight conditions., 資料番号: AA0063742021, レポート番号: JAXA-SP-07-016}, pages = {131--136}, publisher = {宇宙航空研究開発機構, Japan Aerospace Exploration Agency (JAXA)}, title = {Numerical analysis of helicopter BVI noise in turning flight}, volume = {JAXA-SP-07-016}, year = {2008} }